1. Technical Field
The present invention relates in general to a method and system for data processing and in particular to an improved method and system of user interface to a data processing system. Still more particularly, the present invention relates to an improved method and system for simultaneous operation of multiple display control devices, such as a pair of joysticks.
2. Description of the Related Art
There has been great interest in providing Internet access at minimal economic cost. While most computers now are pre-configured for Internet access, a significant percentage of households still do not have a personal computer. Thus, it has now been proposed to provide a data processing system that, much like a VCR, may be connected to a television set and used in lieu of a personal computer to provide World Wide Web access through a conventional remote control device associated with the system unit. Such a system enables the television to become, in effect, a "Web" appliance. The viewer can rapidly switch between conventional television and Internet access using the remote control unit. All of the conventional "Internet" access tools and navigational functions are preferably "built-in" to the system and thus hidden to the user.
The remote control unit used to control the Web appliance is battery-powered and will typically include an infrared source, such as a light emitting diode (LED), which cooperates with a phototransistor in a receiver unit to effect the transfer of control signals for the appliance. An infrared control unit, however, is not easily adaptable for use in providing control of computer games, which use joysticks or glove control devices, because many of these games involve multiple players. In particular, multiple infrared remote devices interfere with each other when used in the same physical environment. This problem has sought to be addressed in the prior art by modifying the control units. Thus, for example, one approach to the problem of eliminating interference between control signals from multiple IR devices is to interlace control signals with quiescent periods during transmission. This technique is disclosed in U.S. Pat. No. 5,331,450. The control signals are received and validated by the receiver based on the quiescent periods. Another approach, illustrated in U.S. Pat. No. 4,313,227, assigns each control unit with a specific discrete carrier frequency. The receiver includes a switching circuit that is automatically controlled by a digital processor for selectively tuning the receiver to receive information from each control unit separately in a predetermined sequence.
Although these approaches enable the simultaneous use of a pair of infrared joystick devices, they requires specialized circuitry in each control unit as well as complex differentiation circuitry at the receiver. This is undesirable, especially in the context of a Web appliance, where it is a goal to reduce the complexity of the device as well as the machine interaction required by the user.